Steam-pipe covering



(No Model.)

P. L. BARTLETT. STEAM PIPE COVERING.

No. 417,768. Patented Dec; 24, 1889.

wl I Invenbon UNITED STATES PATENT OFFICE FRANK L. BARTLETT, OF PORTLAND, MAINE.

STEAM-PIPE COVERING.

SPECIFICATION forming part of Letters Patent No. 417,768,dated December 24:, 1889.

Application filed "jeptember Z1, l889- Serial No. 324,654:- (No model.)

To aZZ whom it may concern:

Be it known that I, FRANK L. BARTLETT, a

v citizen of the United States, residing at Portland,in the county of Cumberland and State of Maine, have invented certain new and useful Improvements in Steam-Pipe Coverings; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

My invention relates to a non-conducting covering for steam-pipes, boilers, &c. andthe object of the invention is to produce a fabric which may be cheaply made, easily applied, and which shall have such a structure as will prevent to the greatest possible extent the radiation of heat.

My invention consists of a steam-pipe covering the body of which is composed of wood or other pulptmixed with sawdust or other granular.material and having a laminated structure with laminations extending longitudinally or parallel with the surface, the adjacent laminae being united by the knitting together of the pulp fibers.

I have illustrated my invention in the accompanying drawings, in which- Figure 1 is a side elevation showing a part section. Fig. 2 is an end elevation, and Fig. 3 is a central longitudinal section showing the covering as applied to a steam-pipe.

The pipe-covering, as shown in the drawings, is cylindrical in form and has a center or body A of pulp mixed with sawdust in about equal proportions and laid with a laminated structure having air cells or spaces, which extend concentrically and parallel to the surfaces of the cylinder. The presence of the sawdust within the pulp forms a great number of air-cells which separate the adjacent layers of pulp. The effect of this formation on the material is to render it a perfect non-conductor of heat, the air-cells being flattened and most numerous in a transverse direction. It is also found that whereas pure pulp tends to shrink very materially when it dries, pulp and sawdust united in this manner shrink but very little. On the outside and inside surfaces of the cylinder I have formed a very thin layer A and C of substantially pure pulp, which, being more close and compact than the pulp and sawdust, entirely prevents any current of air from passing through the material transversely.

The pulp and sawdust may be mixed in any desired proportion, according to the amount of strength desired in the material; but, the sawdust being the cheaper material, it is desirable to use as large a proportion as possible. In place of sawdust I may incorporate with the pulp any other granular material which will separate the fibers of the pulp to form the necessary air-cells.

One orboth of the layers A C may be dispensed with, leaving the covering composed wholly of the pulp and sawdust. In place of wood-pulp, which I prefer to use on account of its cheapness, any pulpable fiber may be used.

It is evident that the tube here shown and claimed may be used for many other purposes besides steam-pipe cove1'ingas, for instance, for conduits for underground wires. I am aware that pipe-covering has been made of concentric layers of paper cemented together with fibrous and granular material; but I do not claim such structure.

My structure has the advantage over that disclaimed from the fact that it can be made more cheaply, being, as itis, in one piece and not built up of numerous pieces. It can be worked readily by cutting or sawing, as the other cannot without tearing it to pieces, and it is a better non-conductor, because the structure is more open, no part of it being solidly compressed, as on the layersof paper in the covering mentioned.

In Fig. 3 I have illustrated the manner in which I prefer to apply my covering to a steam or other pipe. E represents the pipe,

and D is a ring of metal interposed between the pipeand the covering at each end of the section.

I claim- The herein-described covering for steampipes and other like purposes, which consists of pulp or other fibrous material mixed with In testimony whereof I affix my signature in a granular material, as sawdust, and formed presence of two Witnesses. with a laminated structure, the laminations extending parallel With the surface, the fibers FRANK L. BARTLETT of adjacent laminae knitting together to unite WVitnesses: the mass, substantially as shown and cle- S. WV. BATES,

scribed. ARTHUR N. DENNIS. 

